close NX
in folder: C:\Program Files\UGS\NX 8\NXNASTRAN\conf
(or something alike)
look for a file called nast7.rcf (might be nast8, not sure what version of nastran is in NX8)
open it in notepad
add the line:
parallel=8
save file
NX 7.5.5.4 with Teamcenter 8 on win7 64
Intel Xeon @3.2GHz
8GB RAM
Nvidia Quadro 2000